Borehole inclinometer



Dec. 26, 1944. F, G. BQUCHER k 23655999 r BORE HOLE INCLINOMETER FiledDec. 18, 1942 WMM ArroRA/Ex -V Patented Dec. 26; 1944 t BOREHOLEINCLINOMETER,

, Frank G. Boucher, Tulsa, Okla., assignor to i Standard Oil DevelopmentCompany, a corporation of Delaware Application December 18, 1942, SerialNo. 469,499

The present invention is directed to an inclinometer particularlysuitable for bore hole operations.

VWhen conducting operations in bore holes or at other placesinaccessible to the operator, it is frequently desirable to determinethe inclination of a tool or device. Means for indicattng inclinationare at present known to the art, but they have usually been foundunsatisfactory either because they are incapable of giving a record orbecausathey are unduiy complicated.

It is an object of the present invention to produce an improvedinclinometer.

are arranged to produce a beam of light with paralle! rays extendingalong the longitudinal axs of casing ll when .the casing isperpendicular. From the above description it will be apparent that whenthe casing is perpendicular the beam of light from the Optical tube willimpinge on the center of shutter l2.

In the embodiment illustrated in Figures 1 and 2', the pendulum 20 ismounted on gimbals 24 and power for operating lamp 22'is transmittedthereto through the gimbal ring by means of con- More particularly it isan object of the present invention to devise a cable suspended toolwhich will give to an operatr at the surface of the earth a continuousindication of the inclination of a tool in a bore hole.

i Other objects and advantages of the present invention may be' seenfrom reading the following description taken with the drawing in whichFigure 1 is an elevation partly in section of a preferred embodiment ofthe present nvention.

Flgure 2 is a view taken along the line II-II of Figure 1.

Figure 3 is a top view of the shutter with which the device of figure 1is provided.

4 is a view of a typicai record which maybebtainedbythedevicaand Figur-e5 is a fragmenter-y view illustrating another means of mounting thependulum of the device. i

Mounted within a casing orbomb il suitable for Iowering in a bore holeis a crcular shutter 12 arranged -for rotation in the casing withtheplane of the shutter at right angles to the longitudinal axis of thecasing. A suitable means for and 2 to rotate theflshutter for a motorl'lwithitm dingshaft llprovidcd withagearl! tocooperatewiththe ductors25 and commutators 26 as appears in the drawing. A cable 21 is arrangedsuspending the device and power is transmitted down through the cablethrough conductors 28 for operating both motor l'lV and lamp 22.

Mounted in casng H `in the upper end thereof above shutter [2 is a lightsensitive means. A v

satisfa'ctory arrangement is that shown in the drawing comprising a'pairof photocells 29 and 30 with a concave mirror 3l mounted above thephotocells. It will be evident that the arrangement of photocells andthe-mirror is such that any light transmitted from 'lamp 22 throughshutter |2 will be effective to aetuate either photocell 29 or photocell30. The signa1 received by the pair of photocells 29, 30 is transmittedthrough conductors 32,.33 to amplifier 34. The amplified signal is thentransmitted through insulated conductors 35 contained within thesuspending cable to a recording galvanometer, not shown, arranged at thesurface of the earth.

A top view ofa suitable shutter for the device ris shown in Figure 3. Aportion 36 is removed from the shutter so that when the axis-of casingll is Vertical little or no light will be-passed by shutter l2 lfromsource 22 tophotocells 29, 30. However, Upon deviation of casing ll fromthe Vertical lightl will be transmitted from the lamp to the photocellswith each 'rotation of the shutter. 'Iheopening 36intheshutterissoarranged that with increasing displacement of the axisof casing H from the vertical end is a progresively increased time ofexposure of the photocelis to light from the lamp. In other words, whenthe casing ll deviatesfromthe verticalapulseis transmitted by thephotocells with each revolution of the-shutter, the duration -of thepulses being a function of the deviaton of the casing fromthevertical.

Aporfionofatypicalrecordobtainedfromthe deviceisshowninli'iguret'Ihisfignreillustrafes astripoffllmuponwhicharecordisproduced byabeamoflighttransmittedfromagalvanometer connected wlththe Dhotocellelectrie cells. Nmn.

ber 40 designates the strip of film and number ll the record produced bythe galvanometer electrically connected to the photo electric cells. Asshown in the record, two pulses have been indicated by the galvanometerindicated by the portions 42 and 43 of the curve. In this record 42 isof shorter duration than 43 indicating that the inclination of the devcehas increased from the point at which 42 was measured to the point atwhich 43 was indicated.

A modiflcation of the means for suspending the pend um is illustrated inFigure 5. In this embodiment a ball 44 is attached to the pendulum and amember 45 adapted to be secured to the casing defines a suitable socketto cooperate with the ball. In this embodiment leadwires 46 connect lamp22 to the source of power. The leadwires are of ample length to allowthe pendulum to move freely in all directions. The remainder of theapparatus according to this modiflcation may be the same as in Figure 1and accordingly is not again illustrated.

It will be obvious that the depth of casing H should preferably beindicated simultaneously with its inclination. Suitable devices forindicating the depth of a cable suspended tool are conventional to theart and may, of course, be used to indicate or record the depth ofcasing ll while the inclination of the casing is being indicated. Sincedevices for indicating the depth of a tool are well known to the artsuch a devce has not been illustrated in the drawing. In like manner,suitableigalvanometers for recording the output of the photo electriccells are also well known to the art and have not been specificallyshown. It will be apparent that any conventional means may be used inconjunction with the embodiments described trerein.

Having fully described and illustrated the present invention, what Idesire to claim is:

' 1. A bore hole inclinometer comprising-irrcombination an elongatedcasin'g, a pendulum mounted in the lower portion of said casing` formovement in all directions, a source of lightcarried by said pendulum,means arranged for project- .ing a beam of light from said source alongthe longitudinal axis of said casing when said casing is perpendicular,a photo velectric cell means mounted in the upper portion of saidc'asing, a circular shutter mounted for rotation between said lightsource and said photo electric cell means having an Opening from itscenter to its periphery progressively larger than a segment of saidcircle, means arranged to give said snutter constant rotary speed,meansv arranged to amplify the signal received by the photo electriccell means and to transmit it to a galvanometer.

2. A devce in accordance with claim 1 in' which the photo electric cellmeans comprises a pair of photo electric cells mounted back to back infront of a curved mirror and arranged to receive light transmittedthrough said shutter.

FRANK G. BOUCHER.

